US3579764A

US3579764A - Process for producing textured yarns

Info

Publication number: US3579764A
Application number: US802640*A
Authority: US
Inventors: William H Kieffer
Original assignee: Indian Head Inc
Current assignee: Indian Head Inc
Priority date: 1969-02-26
Filing date: 1969-02-26
Publication date: 1971-05-25
Anticipated expiration: 1988-05-25

Abstract

A process for producing textured yarns from synthetic fiber yarns including the steps of knitting the yarn, heating the knit yarn to stabilize it prior to dyeing, dyeing the yarn, unraveling the dyed yarn and texturing the dyed yarn. The resulting yarns exhibit combinations of bulk and uniformity which are superior to those previously available commercially.

Description

United States Patent [72] Inventor William H. Kieffer Summit, NJ. [21} Appl. No. 802,640 22] Filed Feb. 26, 1969 [45] Patented May 25, 1971 [73] Assignee Indian Head Inc.

New York, N.Y. Continuation-impart of application Ser. No. 758,677, Sept. 10, 1968, now abandoned.

[54] PROCESS FOR PRODUCING TEXTURED YARNS 10 Claims, 1 Drawing Fig. [52] U.S. Cl 28/72.1l, 28/72.16 [51] Int. Cl D02g 1/20 [50] Field ofSearch 28/72.l1, 72.16; 8/ 1 54 [56] References Cited UNITED STATES PATENTS 2,439,813 4/1948 Kulp et a1. 161/173 FILAMENT YARN Primary ExaminerRobert R. Mackey AttarneyBrumbaugh, Graves, Donohue & Raymond ABSTRACT: A process for producing textured yarns from synthetic fiber yams including the steps of knitting the yarn, heating the knit yarn to stabilize it prior to dyeing, dyeing the yarn, unraveling the dyed yarn and texturing the dyed yarn. The resulting yarns exhibit combinations of bulk and uniformity which are superior to those previously available commercially.

KNIT

TEXTURING HEAT DYEING CONDITIONS DEK-NIT PATENTEUmwzsm 3579164 FILAMENT YARN I N VEN '1 0R WILLIAM H. KIEFFER Bysw fih l (CM A mvsrs 1 l PROCESS FOR PRODUCING TEXTURED YARNS knitting machine, and the tubing is heated sufficiently to cause the yarn to be permanently set in the convolutions caused by its knitted condition. The knit tubing is then deknit to provide a yarn which has characteristic texture and bulk. Fabrics made from knit/deknit yarns have a characteristic handle and appearance which, while desirable for some uses, are unsuitable for many commercially important types of fabrics.

Among other known procedures in the textile industry for producing texture in filament yarns of synthetic polymers are the texturing operation utilizing a stuffer box and the operation which applies a false twist to the yarn. A stuffer box is described, for example, in Chapter 7 of the publication Textured Yarn Technolog Vol. 1, I967, of the Monsanto Company. (Library of Congress Catalog Card No. 67-15639) The stuffer box imparts a characteristic crimp or texture to filament yarns. Procedures which apply crimp or texture by false twisting are discussed in Chapter 3 of the same publication.

The dyeing of filament yams is generally performed after the texturing operation in order to improve dye uniformity over that which can be obtained on untextured yarns. Most textured yarns are dyed in the form of muffs or packages.

These conventional dyeing procedures generally result in loss of texture in the dyed yam to a greater or less degree depending on the type of texture and the processing condition.

it has now been discovered that a level dyed textured filament yarn of highly desirable texture can be provided in an economical manner by combining in sequence a knit/heat-set operation followed by dyeing, deknitting and a subsequent texturing step. The filament yarn is knitted, preferably as a tubing, and heat-set in the knitted condition. The tubing is then wound onto a dye package and dyed in accordance with conventional processes. After drying, the dyed tubing is deknitted and fed to a texturing'device, such as a stufier box, a false twist machine .or other texturing device. The result is a level dyed textured yarn which, when knitted or woven into a fabric for use in garments, home furnishings, or industrial applications provides a fabric of improved hand, texture and uniformity.

The process of the invention is further illustrated by the flow diagram of FIGURE 1 of the attached drawing.

Undyed yarns of the. same high quality are obtained by omitting the dyestuff or colorant from the dye bath during the dyeing step. All other conditions, including the presence of moisture and the pressure and temperature conditions used, remain the same. The resulting undyed yarns, when knitted into finished goods, give an outstanding hi-bulk and an excellent finish and hand to the fabric.

The first step of the process of this invention, that of knitting and heat-setting to form a crinkle-type yarn, is similar to the process known to the prior art with the important exception that the heat-setting is accomplished at a temperature below that required for pennanent crimping of yarn from the particular polymer from which the filament is made. On the other hand, the heat-set temperature must be higher than the dyeing temperature used for the particular yam being treated so that the heat-set knit yarn will be stabilized againstshrinking during the dyeing process. For example, the temperature used for dyeing polyester yarns is in the order of 200270 F. the heat-set temperature to be used with such yarn must be in excess of such dyeing temperature, and a temperature of about 300 F. has been found to be suitable. As another example, nylon filament yams are usually dyed at a temperature in the range of 2l2 F. [have observed that excellent dyeing results may be obtainedwhen suchnylon yarn in knitted form has been heat-set before dyeing at a temperature of about 225 F.

On the other hand, the heat-set temperature for the knitted yarn should be lower than the temperature which will be used in the final texturing step in order to secure optimum improvement in bulk, stretch and texture of the finished dyed yarn.

After heat-setting, as described, the knitted yarn may be dyed in a conventional manner. it has been observed that the heat-set knitted tubing forms compact dye packages which are substantially free from shrinkage during dyeing and thatlevel dyeing is readily accomplished.

The deknitting step of the present invention involves merely the unraveling of the dyed yam tubing. The unraveled yarn is then fed to a texturing device such as a stuffer crimper or a false twist machine, either directly or after being subjected to any desired repackaging or twisting or plying operation or operations as intermediate steps. The yarn or tubing can be further treated after dyeing provided that such treatments are carried out at temperatures suitably below those of the final texturing step. The texturing step is carried out in a conventional manner and at a temperature which imparts the desired pennanent texturing to the dyed yarn. The temperature at which these devices are operated is sufficiently high to substantially remove the crimp imparted to the yarn during the heat-setting of the knitted yarn tubing and to produce the permanent texturing crimp in the yarn. V

The following examples further illustrate the process of the present invention:

EXAMPLE I ISO-denier polyester filament yarn is knitted on a continuous circular knitting machine having a 224-needle head. As the knitted tubing leaves the machine, it is heat-set at 300 F 1 The yarn tubing is then wound on a suitable core into a dye package and dyed following standard procedures at 265 F.

After drying, the dyed tubing is deknitted and fed to a stuffer crimper, which is operated at a temperature of 325 F. This temperature is sufficiently high to substantially remove the crimp imparted by the first heat-setting step described above before the permanent crimp imparted by the stuffer crimper becomes effective.

The resulting yarn .is dyed level and when knitted into finished goods, gives outstandingly high bulk and an excellent finish and hand to the fabric.

EXAMPLE ll Example I was repeated, except that the dyestuff was omitted from the'dye bath used in the dyeing step. All other conditions remained the same. The resulting yarn, when knitted into knitted cellent finish and hand to the finished goods.

EXAMPLE lll 70-denier nylon filament yarn is knitted on a continuous circular knitting machine having a 340-needle head. As the knitted tubing leaves the machine it is heat-set at 225 F. The yarn tubing is then wound into a dye package and dyed following standard procedures at 2 10 F. After drying, the dyed tubing is deknitted and fed to a stuffer crimper, which is operated at a temperature of 380 F.

goods, gave outstanding hi-bulk and an ex- 3 EXAMPLE 1v EXAMPLE V l-denier polyester filament yarn is knitted on a continuous circular knitting machine having a 224-needle head. As the knitted tubing leaves the machine, it is heat-set at 300 F. The yarn tubing is then wound on a suitable core into a dye' package and dyed following standard procedures at 265 F.

After drying, the dyed tubing is deknitted and fed to a stuffer crimper, which is operated at a temperature of 325 F. This temperatureis sufficiently high to substantially remove the crimp imparted by the first heat-setting step described above before the permanent crimp imparted by the stuffer crimper becomes effective.

The resulting yarn is dyed level and when knitted into finished goods gives outstandingly high bulk and an excellent finish and hand to the fabric.

EXAMPLE Vl ISO-denier polyester filament yarn is knitted on a continuous circular knitting machine having a 224-needle head. As the knitted tubing leaves the machine, it is heat-set at 300 F. The yarn tubing is then wound on a suitable core into a dye package and dyed following standard procedures at 265 F.

After drying, the dyed tubing is deknitted and fed through a false twist texturing machine with 58 turns per inch at 410 F. and a spindle speed of 200,000 r.p.m.

After false twisting the dyed filament yarns may be autoclaved by standard procedures and be used as a set textured" yarn or used without autoclaving as a stretch textured yarn.

EXAMPLE Vll 70-denier nylon filament yarn is knitted on a continuous circular knitting machine having a 340-needle head. As the knitted tubing leaves the machine, it is heat-set at 225 F. The yam tubing is then wound on a suitable core into a dye package and dyed following standard procedures at 210 F.

After drying the'dyed tubing is deknitted and fed through a false twist texturing machine at a spindle speed of 225,000 r.p.m. with 76 turns per inch at a temperature'of 437 F. This temperature is sufficiently high to substantially remove the crimp imparted by the first heat-setting step described before the permanent crimp imparted by the false twist machine becomes effective.

After false twisting, the dyed textured filament yarns may be autoclaved by standard procedures and be used as a set textured yarn or used without autoclaving as a stretch textured yarn.

It will be appreciated that various modifications and changes can be made in the herein disclosed process and product by those skilled in the art without departing from the essence of the invention and that accordingly the invention is to be limited only within the scope of the appended claims.

.- 4 mam; n l. A method of making a dyedtexturedfilament yam of a heat-settable synthetic polymer comprising the steps of knitting filament yarn from a synthetic polymer in a circular manner to form a knit tubing,

passing the knit tubing through a heating step to set the yarn at a temperature intermediate between normal dyeing temperatures and normal texturing temperatures for the yarn, 1

forming a dye package of the knit tubing and dyeing the deknitting the dyed tubing,

texturing the yarn by a method which includes heat treatment at a temperature above that used to set the knit yarn before dyeing. I t 2. The method of claim 1, wherein the heat-settable synthetic polymer yarn is selected from the group consisting of polyamides, polyesters, polyolefins, cellulose acetates, biconstituent fibers, copolymers and graft polymers.

3. The method of claim 1, wherein the texturing step is accomplished by using a stufier crimper.

4. The method of claim 1, wherein the texturing step is accomplished by using a false twist machine.

5. A method of making a dyed textured filament yarn of a heat-settable synthetic polymer comprising the steps of knitting a filament yarn from a synthetic polymer in a circular manner to form a knit tubing,

heat-setting the knit tubing at a temperature intermediate between normal dyeing temperatures and normal texturing temperatures for the yarn,

uniformly dyeing the knit yarn at a dyeing temperature below the said heat-setting temperature,

deknitting the dyed yarn, and

texturizing the yarn by a method'including heat treatment at a temperature higher than the said heat-setting temperature but insufficient to damage the yarn.

6. The method of claim 5, wherein the heat-settable synthetic yarn is selected from the group consisting of polyamides, polyesters, polyolefins, cellulose acetates, biconstituent fibers, copolymers and graft polymers.

7. The method of claim 6, wherein the texturing step is accomplished using a stuffer crimper.

8. A method of making a textured filament yarn of a synthetic polymer comprising the steps of knitting a synthetic polymer filament yarn in a circular manner to form a knit tubing, passing the knit tubing through a heating step at a temperature intermediate between normal dyeing temperatures and normal texturing temperatures for the yarn to set the yarn, fonning a dye package of the knit tubing and subjecting the package to conditions of temperature, pressure and moisture normally used in dyeing the yarn, deknitting the tubing, and texturing the yarn by a method which includes heat treatment at a temperature above that used to set the knit yarn before fluid treatment in package form.

9. The method of claim 8, wherein the texturing step is accomplished by using a stufi'er crimper.

10. The method of claim 8, wherein the synthetic polymer yarn is selected from the group consisting of polyamides, polyesters, polyolefins, cellulose acetates, biconstituent fibers, copolymers' and graft polymers.

Claims

2. The method of claim 1, wherein the heat-settable synthetic polymer yarn is selected from the group consisting of polyamides, polyesters, polyolefins, cellulose acetates, biconstituent fibers, copolymers and graft polymers.
3. The method of claim 1, wherein the texturing step is accomplished by using a stuffer crimper.
4. The method of claim 1, wherein the texturing step is accomplished by using a false twist machine.
5. A method of making a dyed textured filament yarn of a heat-settable synthetic polymer comprising the steps of knitting a filament yarn from a synthetic polymer in a circular manner to form a knit tubing, heat-setting the knit tubing at a temperature intermediate between normal dyeing temperatures and normal texturing temperatures for the yarn, uniformly dyeing the knit yarn at a dyeing temperature below the said heat-setting temperature, deknitting the dyed yarn, and texturizing the yarn by a method including heat treatment at a temperature higher than the said heat-setting temperature but insufficient to damage the yarn.
6. The method of claim 5, wherein the heat-settable synthetic yarn is selected from the group consisting of polyamides, polyesters, polyolefins, cellulose acetates, biconstituent fibers, copolymers and graft polymers.
7. The method of claim 6, wherein the texturing step is accomplished using a stuffer crimper.
8. A method of making a textured filament yarn of a synthetic polymer comprising the steps of knitting a synthetic polymer filament yarn in a circular manner to form a knit tubing, passing the knit tubing through a heating step at a temperature intermediate between normal dyeing temperatures and normal texturing temperatures for the yarn to set the yarn, forming a dye package of the knit tubing and subjecting the package to conditions of temperature, pressure and moisture normally used in dyeing the yarn, deknitting the tubing, and texturing the yarn by a method which includes heat treatment at a temperature above that used to set the knit yarn before fluid treatment in package form.
9. The method of claim 8, wherein the texturing step is accomplished by using a stuffer crimper.
10. The method of claim 8, wherein the synthetic polymer yarn is selected from the group consisting of polyamides, polyesters, polyolefins, cellulose acetates, biconstituent fibers, copolymers and graft polymers.